Rh-Mediated Isoimmune Hemolytic Disease Suzanne Reuter MD SDPA ~ Spearfish September 8, 2016

Objectives Understand heme catabolism Define Rh-isoimmune disease as it relates to a newborn Review abnormal indices in Rh-isoimmune disease Discuss therapies for hyperbilirubinemia Review complications of exchange transfusion Identify complications of phototherapy

Day of Delivery 34 weeks gestation Maternal anti-D (1:64) and anti-C (1:8) 2240 grams (5 lb) Apgars 71, 85 Initial respiratory compromise necessitating use of: NIPPV NCPAP NC

Day of Delivery Physical Exam notable for: Pallor Jaundice Mild subcostal retractions Grade II/VI systolic murmur Mildly hyperdynamic precordium Liver 4 cm below the right costal margin Palpable spleen

Day of Delivery Initial lab results: Hematocrit: 22.6 % Platelets: 119,000 Reticulocyte count: 23% Unconjugated bilirubin: 9.1 Conjugated bilirubin: 0.1 Blood type: A+ (antibody +) Maternal blood type: A- (antibody + x2) 16 hours of age: Unconjugated bilirubin:18.8

What’s the concern?

Heme Catabolism

Kernicterus – Bilirubin-Induced Neurologic Dysfunction Bilirubin staining of the basal ganglia, hippocampus, substancia nigra, brainstem nuclei Neuronal necrosis Choreoathetosis cerebral palsy High-frequency hearing loss Paralysis of upward gaze Dental enamel hypoplasia Cognitive function intact Bilirubin encephalopathy

Treatment

Treatment Intravenous Immunoglobulin – A LOT!

RE cells – {macrophages} Destruction of old RBCs and WBCs

Threshold Bilirubin nomograms for 35 weeks and older

Threshold B/A ratio > 7 →→→ Premature infants: Half the first 2 numbers in the weight 2240 grams = half of 22 = 11 Bilirubin/albumin ratio (term infants) B/A ratio > 7 →→→ All bilirubin binding sites on albumin are saturated At MN of DOL 1, b/a ratio was 6.

Exchange Transfusion Underwent exchange transfusion #1.

Exchange Transfusion - Effects Positive Unconjugated bilirubin decreases Negative Acidosis Hypernatremia Hypocalcemia Hypoglycemia Hyperkalemia Air embolus Infection Clots Arrhythmia BP instability Intraventricular hemorrhage (premature infants) Necrotizing Enterocolitis (NEC) Increase in conjugated bilirubin (peak 0.7) Rebound of UB usually to 2/3 pre-exchange level

s/p Exchange Transfusion Bilirubin rebounded to 16.3 and albumin dropped to 2.9 B/A ratio was 5.6

Complicating Factors…

Maternal Drug Use Suboxone (buprenophine) – Treatment of narcotic addiction Withdrawal in babies following birth (usually peak at 3d): Hypertonia Tremors Agitation Myoclonic jerks Apnea Bradycardia Withdrawal seen in over 50% of babies exposed to suboxone in utero. Previous child in NICU prolonged time when mom was on Methadone

Neonatal Abstinence Syndrome Agitation, sneezing, jitteriness Treated with Fentanyl (narcotic), Phenobarbital (anti-seizure) On Neosure

Photosensitivity Skin Rash

Photosensitivity Skin Rash Other effects of phototherapy include increased nevi development in those infants exposed to PTX, hyperthermia, electrolyte imbalances, retinal photoreceptor degeneration, and insensible water losses.

Remaining hospital course… Struggled with nipple feeds Slowly weaned off Fentanyl and Phenobarbital Phototherapy rash completely resolved with no residual skin changes

Questions